They also warn that tackling the problem is critical, as there is clear evidence that effects from abuse are carried into adulthood, making it more likely abused children will grow up to be violent, and engage in risky sexual behaviour as adults.

The findings come as child protection services in the UK are being reviewed in the wake of the Baby P case. The figure of one in 10 children is broadly accepted across the medical world, the report adds. Ruth Gilbert of the Institute of Child Health at University College London, said: "Child maltreatment is common, and for many it is a chronic condition, with repeated and ongoing maltreatment merging into adverse outcomes throughout childhood and into adulthood. Scarce reporting to child-protection agencies is a cause for concern, and we need to find out if maltreatment is being recognised and dealt with."

Cathy Spatz Widom of City University of New York added: "The burden is substantial on the children themselves and on society." The definitions of abuse are wide-ranging. These range from violence and rape, to neglect and emotional abuse such as making a child feel worthless or unwanted.

Parents account for most maltreatment except sexual abuse, which is usually committed by other family members, or an acquaintance, researchers say.

The study says "it is estimated" at least 15 per cent of girls and five per cent of boys have been exposed to sexual abuse of some kind by the age of 18, and that between five and 10 per cent of girls and one to five per cent of boys are exposed to penetrative sexual abuse.